windows C++ UDP 多播

// 服务器端
// Server.cpp : Defines the entry point for the console application.
//

#include
#include
#include
using namespace std;

#pragma comment(lib, “ws2_32.lib”)
const int MAX_BUF_LEN = 10;

void main()
{
    WORD wVersionRequested;
    WSADATA wsaData;
    int err;

    // 启动socket api
    wVersionRequested = MAKEWORD(2, 2);
    err = WSAStartup(wVersionRequested, &wsaData);
    if (err != 0)
    {
        return;
    }

    if (LOBYTE(wsaData.wVersion) != 2 ||
        HIBYTE(wsaData.wVersion) != 2)
    {
        WSACleanup();
        return;
    }

    // 创建socket
    SOCKET connect_socket;
    connect_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (INVALID_SOCKET == connect_socket)
    {
        err = WSAGetLastError();
        printf(“error! error code is %d/n”, err);
        return;
    }

    SOCKADDR_IN sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(3779);
    //sin.sin_addr.s_addr = INADDR_BROADCAST;
    sin.sin_addr.s_addr = inet_addr(“255.255.255.255”);//设置广播地址,window下用这种形式方可

    bool bOpt = true;
    //设置该套接字为广播类型
    setsockopt(connect_socket, SOL_SOCKET, SO_BROADCAST, (char*)&bOpt, sizeof(bOpt));

    int nAddrLen = sizeof(SOCKADDR);

    char buff[MAX_BUF_LEN] = “”;
    while (1)
    {
        sprintf_s(buff, “%s”,“ss”);

        // 发送数据
        int nSendSize = sendto(connect_socket, buff, strlen(buff), 0, (SOCKADDR*)&sin, nAddrLen);
        if (SOCKET_ERROR == nSendSize)
        {
            err = WSAGetLastError();
            printf(“error!, error code is %d/n”, err);
            return;
        }
        printf(“Send: %s/n”, buff);
        Sleep(500);
    }
}

// 客户端
// Client.cpp : Defines the entry point for the console application.
//

#include
#include

#pragma comment(lib, “ws2_32.lib”)
const int MAX_BUF_LEN = 255;

void main()
{
    WORD wVersionRequested;
    WSADATA wsaData;
    int err;

    // 启动socket api
    wVersionRequested = MAKEWORD(2, 2);
    err = WSAStartup(wVersionRequested, &wsaData);
    if (err != 0)
    {
        return;
    }

    if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2)
    {
        WSACleanup();
        return;
    }

    // 创建socket
    SOCKET connect_socket;
    connect_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (INVALID_SOCKET == connect_socket)
    {
        err = WSAGetLastError();
        printf(“error! error code is %d/n”, err);
        return;
    }

    // 用来绑定套接字
    SOCKADDR_IN sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(3779);
    sin.sin_addr.s_addr = 0;

    // 用来从网络上的广播地址接收数据
    SOCKADDR_IN sin_from;
    sin_from.sin_family = AF_INET;
    sin_from.sin_port = htons(3779);
    sin_from.sin_addr.s_addr = INADDR_BROADCAST;

    //设置该套接字为广播类型，
    bool bOpt = true;
    setsockopt(connect_socket, SOL_SOCKET, SO_BROADCAST, (char*)&bOpt, sizeof(bOpt));

    // 绑定套接字
    err = bind(connect_socket, (SOCKADDR*)&sin, sizeof(SOCKADDR));
    if (SOCKET_ERROR == err)
    {
        err = WSAGetLastError();
        printf(“error! error code is %d/n”, err);
        return;
    }

    int nAddrLen = sizeof(SOCKADDR);
    char buff[MAX_BUF_LEN] = “”;
    int nLoop = 0;
    while (1)
    {
        // 接收数据
        int nSendSize = recvfrom(connect_socket, buff, MAX_BUF_LEN, 0, (SOCKADDR*)&sin_from, &nAddrLen);
        if (SOCKET_ERROR == nSendSize)
        {
            err = WSAGetLastError();
            printf(“error! error code is %d/n”, err);
            return;
        }
        buff[nSendSize] = ‘/0’;
        printf(“Recv: %s/n”, buff);
    }
}